This invention relates to high power compression assembled thyristors, and more specifically relates to a novel spring biased center gate lead structure for such devices.
Compression assembled housings for high power semiconductor housings are well known, and generally comprise a pair of massive copper pole pieces coaxially fixed to the opposite ends of a support ceramic cylinder and projecting into the cylinder. A semiconductor wafer having the necessary P-N junctions therein to define a thyristor is then fixed in position between the opposite flat, parallel interior surfaces of the respective pole pieces. This wafer is commonly termed a "junction". The junction has main electrodes on its opposite surfaces, and these are engaged with high pressure by the respective pole pieces when they are put under clamping pressure.
The gate or control electrode for the thyristor is commonly located at the center of the top of the wafer or junction. Thus, a gate lead must be fixed to the center gate electrode and attached to a gate pin which extends through the ceramic insulator during the assembly of the housing. Such gate leads can break during assembly or can make poor contact to the center junction electrode or pin. The assembly operation is therefore tedious and the gate connection unreliable.